The authors induced CHF in rats by binding their left coronary artery. This caused the rats to have severe heart failure with elevated left ventricular end diastolic pressure (LVEDP) and reduced sodiumconcentrations in the blood. When the authors examined the kidney tissue of the CHF rats, they found a marked increase in the amount of AQP2s. Further, most of the AQP2 was in the apex of the cell membrane. The control rats had no increase in AQP2s and their AQP2s were found more within the cell cytoplasm and less prominently in the apex of the cell membrane.

congestive heart failure

DEFINITION:

A clinical syndrome due to heart disease, characterized by breathlessness and abnormal sodium and water retention, often resulting in edema. The congestion may occur in the lungs or peripheral circulation or both, depending on whether the heart failure is right-sided or general.

altered

DEFINITION:

1. Having been made or become different.

2. Castrated; spayed.

3. Abbreviation for "alteration."

regulation

DEFINITION:

1. The act of adjusting or state or being adjusted to a certain standard. 2. In biology, the adaptation of form or behavior of an organism to changed conditions. 3. The power to form a whole embryo from stages before the gastrula.

vasopressin

DEFINITION:

1. One of two octapeptide hormones formed by the neuronal cells of the hypothalamic nuclei and stored in the posterior lobe of the pituitary gland (neurohypophysis), the other being oxytocin. It stimulates the contraction of the muscular tissue of the capillaries and arterioles, raising the blood pressure. It promotes contraction of the intestinal musculature and increases peristalsis, and also exerts some contractile influence on the uterus. It also has a specific effect on the epithelial cells of the distal portion of the uriniferous tubule, augmenting resorption of water independently of solutes, resulting in concentration of urine and dilution of blood serum. Its rate of secretion is regulated chiefly by the osmolarity of the plasma.

2. [USP], A pharmaceutical preparation of the same principle, prepared synthetically or obtained from the posterior pituitary of healthy domestic animals used for food by man; used mainly as an antidiuretic in the treatment of acute or chronic diabetes insipidus, administered intramuscularly as a test of hypothalamo-neurohypophysial-renal function in distinguishing central from nephrogenic diabetes insipidus; it may also be used to stimulate smooth muscle tissue, especially to induce vasoconstriction in the presence of hemorrhage. Called also antidiuretic hormone (ADH).

regulated

DEFINITION:

1. Having been adjusted to a certain standard.

2. In biology, describing the adaptation of form or behavior of an organism to changed conditions.

water channel

DEFINITION:

A channel in the plasma membrane of plant and animal cells that permits passage of water molecules; chemical substances such as vasopressin cause the opening of new channels and increase permeability.

aquaporin-2

DEFINITION:

Also called WCH-CD, this water channel makes the principal cells of the inner medullary collecting duct in the kidneys more permeable to water. Lack of functional aquaporin-2 gene leads to a rare form of nephrogenic diabetes insipidus.

AQP2

DEFINITION:

Aquaporin-2.

renal collecting duct

DEFINITION:

Also known as the tubulus renalis colligens, or renal collecting tubule: That structure of the kidney consisting of the arcuate renal tubule, straight collecting tubule, and papillary duct considered together.

ligation

DEFINITION:

The application of a ligature.

heart failure

DEFINITION:

Inability of the heart to pump blood at an adequate rate to fill tissue metabolic requirements or the ability to do so only at an elevated filling pressure. It can be defined clinically as a syndrome of ventricular dysfunction accompanied by reduced exercise capacity and other characteristic hemodynamic, renal, neural, and hormonal responses.

kidney

DEFINITION:

One of a pair of vertebrate organs situated in the body cavity near the spinal column that excrete waste products of metabolism, in man are bean-shaped organs about 4-1/2 inches long lying behind the peritoneum in a mass of fatty tissue, and consist chiefly of nephrons by which urine is secreted, collected, and discharged into a main cavity whence it is conveyed by the ureter to the bladder.

membrane

DEFINITION:

A thin layer of tissue which covers a surface, lines a cavity, or divides a space or organ.

apical membrane - Pertaining to or located at the apex.

basolateral membrane - Pertaining to the base and sides.

plasma membrane - The structure enveloping a cell, enclosing the cytoplasm, and forming a selective permeability barrier; it consists of lipids, proteins, and some carbohydrates, the lipids thought to form a bilayer in which integral proteins are embedded to varying degrees.

postsynaptic membrane - The area of plasma membrane of a postsynaptic cell, either a muscle fiber or a neuron, that is within the synapse and has areas especially adapted for receiving neurotransmitters.

presynaptic membrane - Area of the plasma membrane of a presynaptic axon that is within the synapse and has sites (active zones) especially adapted for the release of neurotransmitters.

semipermeable membrane - A membrane that permits the passage of a solvent, such as water, but prevents the passage of the dissolved substance, or solute.

fractions

DEFINITION:

1. Portions of something larger.

2. In chemistry, referring to the separable constituents of a substance.

AQP2 expression

DEFINITION:

The process, or the regulation of the process, by which the effects of the aquaporin-2 gene are manifested.

N

DEFINITION:

Symbol for newton , nitrogen , and for normal (solution), used with a number designating the strength of the solution relative to the normal, e.g., N/2 or 0.5 N for half-normal.

relative

DEFINITION:

1. A thing having a relation to or a dependence upon another thing. 2. A person connected with another by blood or marriage. 3. Pertinent, relevant. 4. Not absolute or independent; comparative. 5. Expressed as the ratio of the specified quantity to the total magnitude or to the mean of all quantities involved.

N

DEFINITION:

Symbol for newton , nitrogen , and for normal (solution), used with a number designating the strength of the solution relative to the normal, e.g., N/2 or 0.5 N for half-normal.

immunoblotting

DEFINITION:

See immunoblots .

expression

DEFINITION:

1. The aspect or appearance of the face (or surface of a cell) as determined by the physical or emotional state.

2. The act of squeezing or evacuating by pressure; a term used in pharmacy, surgery, and obstetrics.

3. The detectable effect of a gene.

4. A representation of value, relation, or the like (e.g., ratio).

AQP1

DEFINITION:

Aquaporin-1.

AQP3

DEFINITION:

Aquaporin-3.

water channel

DEFINITION:

A channel in the plasma membrane of plant and animal cells that permits passage of water molecules; chemical substances such as vasopressin cause the opening of new channels and increase permeability.

expression

DEFINITION:

1. The aspect or appearance of the face (or surface of a cell) as determined by the physical or emotional state.

2. The act of squeezing or evacuating by pressure; a term used in pharmacy, surgery, and obstetrics.

3. The detectable effect of a gene.

4. A representation of value, relation, or the like (e.g., ratio).

AQP2

DEFINITION:

Aquaporin-2.

selective

DEFINITION:

Having a high degree of selectivity.

plasma

DEFINITION:

1. The fluid portion of the blood in which the particulate components are suspended. Plasma is to be distinguished from serum , which is the cell-free portion of the blood from which the fibrinogen has been separated in the process of clotting. See blood plasma . 2. The lymph deprived of its corpuscles or cells. 3. A glycerite of starch used in preparing ointments. 4. Cytoplasm or protoplasm.

AQP2 expression

DEFINITION:

The process, or the regulation of the process, by which the effects of the aquaporin-2 gene are manifested.

N

DEFINITION:

Symbol for newton , nitrogen , and for normal (solution), used with a number designating the strength of the solution relative to the normal, e.g., N/2 or 0.5 N for half-normal.

immunocytochemistry

DEFINITION:

The biochemistry of cellular immunology.

labeling

DEFINITION:

1. The marking, tagging, or act of identifying something.2. Providing something with such a characteristic.

radioactive labeling - the marking of a compound by incorporating a radioisotope into it.

apical plasma membrane

DEFINITION:

Indicating the apex of the plasma membrane.

labeling

DEFINITION:

1. The marking, tagging, or act of identifying something.2. Providing something with such a characteristic.

radioactive labeling - the marking of a compound by incorporating a radioisotope into it.

intracellular vesicles

DEFINITION:

Vesicles within a cell.

collecting duct cells

DEFINITION:

The cells of the renal collecting tubule: the arcuate renal tubule, straight collecting tubule, and papillary duct considered together.

trafficking

DEFINITION:

Acting as a transporter.

AQP2

DEFINITION:

Aquaporin-2.

apical plasma membrane

DEFINITION:

Indicating the apex of the plasma membrane.

selective

DEFINITION:

Having a high degree of selectivity.

AQP2 expression

DEFINITION:

The process, or the regulation of the process, by which the effects of the aquaporin-2 gene are manifested.

plasma membrane

DEFINITION:

The structure enveloping a cell, enclosing the cytoplasm, and forming a selective permeability barrier; it consists of lipids, proteins, and some carbohydrates, the lipids thought to form a bilayer in which integral proteins are embedded to varying degrees.

hyponatremia

DEFINITION:

Deficiency of sodium in the blood.

permission

DEFINITION:

Formal consent; authorization.

aquaporin-2

DEFINITION:

Also called WCH-CD, this water channel makes the principal cells of the inner medullary collecting duct in the kidneys more permeable to water. Lack of functional aquaporin-2 gene leads to a rare form of nephrogenic diabetes insipidus.

AQP2

DEFINITION:

Aquaporin-2.

protein

DEFINITION:

Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur, the characteristic element being nitrogen, and which are widely distributed in plants and animals. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a-amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins, and each protein has a unique, genetically defined amino acid sequence which determines its specific shape and function. They serve as enzymes, structural elements, hormones, immunoglobulins, etc., and are involved in oxygen transport, muscle contraction, electron transport, and other activities throughout the body, and in photosynthesis.

binding protein - any of a number of plasma proteins (See below) that bind to hormones of low solubility (chiefly the thyroid and steroid hormones), thus providing a transport system for them; some are specific for particular hormones, while others bind to any sparingly soluble hormones. Called also carrier protein or transport protein (See below).

carrier proteins - A binding protein (See above).

plasma proteins - The hundreds of different proteins present in blood plasma, including carrier proteins (such as albumin, transferrin, and haptoglobin), fibrinogen and other coagulation factors, complement components, immunoglobulins, enzyme inhibitors, precursors of substances such as angiotensin and bradykinin, and many other types of proteins.

transport protein - binding protein (See above).

principal cells

DEFINITION:

1. The fundamental cells of an organ, which usually have a specific function.

2. The principal cells are the chief cells, i.e., the most abundant cells of the parathyroid glands, being polygonal epithelial cells with a granular cytoplasm and vesicular nuclei, arranged in plates or cords, and which are rich in glycogen: the clear cells are more numerous and have relatively large nuclei and clear cytoplasm with few granules, while the dark cells are smaller with smaller and darker nuclei and finely granular cytoplasm with many granules. Intermediate forms also exist.

kidney collecting duct

DEFINITION:

Also known as the tubulus renalis colligens , or renal collecting tubule: that structure of the kidney consisting of the arcuate renal tubule, straight collecting tubule, and papillary duct considered together.

antidiuretic hormone

DEFINITION:

See vasopressin.

vasopressin

DEFINITION:

1. One of two octapeptide hormones formed by the neuronal cells of the hypothalamic nuclei and stored in the posterior lobe of the pituitary gland (neurohypophysis), the other being oxytocin. It stimulates the contraction of the muscular tissue of the capillaries and arterioles, raising the blood pressure. It promotes contraction of the intestinal musculature and increases peristalsis, and also exerts some contractile influence on the uterus. It also has a specific effect on the epithelial cells of the distal portion of the uriniferous tubule, augmenting resorption of water independently of solutes, resulting in concentration of urine and dilution of blood serum. Its rate of secretion is regulated chiefly by the osmolarity of the plasma.

2. [USP], A pharmaceutical preparation of the same principle, prepared synthetically or obtained from the posterior pituitary of healthy domestic animals used for food by man; used mainly as an antidiuretic in the treatment of acute or chronic diabetes insipidus, administered intramuscularly as a test of hypothalamo-neurohypophysial-renal function in distinguishing central from nephrogenic diabetes insipidus; it may also be used to stimulate smooth muscle tissue, especially to induce vasoconstriction in the presence of hemorrhage. Called also antidiuretic hormone (ADH).

VP

DEFINITION:

Abbreviation for vasopressin.

AQP2

DEFINITION:

Aquaporin-2.

apex

DEFINITION:

1. A general term used in anatomical nomenclature to designate the superior aspect of a body, organ, or part, or the pointed extremity of a conical structure such as the heart or lung; called also tip.

2. The point of greatest activity, or the point of greatest response to any type of stimulation, such as electrical stimulation of a muscle.

cell membrane

DEFINITION:

Plasma membrane.

VP

DEFINITION:

Abbreviation for vasopressin.

vasopressin-2 receptor

DEFINITION:

The molecular structure within a cell or on the surface to which the antidiuretic hormone, arginine vasopressin, binds.

AQP2

DEFINITION:

Aquaporin-2.

cell membrane

DEFINITION:

Plasma membrane.

cell membrane

DEFINITION:

Plasma membrane.

AQP2

DEFINITION:

Aquaporin-2.

kidney

DEFINITION:

One of a pair of vertebrate organs situated in the body cavity near the spinal column that excrete waste products of metabolism, in man are bean-shaped organs about 4-1/2 inches long lying behind the peritoneum in a mass of fatty tissue, and consist chiefly of nephrons by which urine is secreted, collected, and discharged into a main cavity whence it is conveyed by the ureter to the bladder.

reabsorb

DEFINITION:

To absorb again; to undergo or to subject to reabsorption.

kidney collecting duct

DEFINITION:

Also known as the tubulus renalis colligens , or renal collecting tubule: that structure of the kidney consisting of the arcuate renal tubule, straight collecting tubule, and papillary duct considered together.

kidney

DEFINITION:

One of a pair of vertebrate organs situated in the body cavity near the spinal column that excrete waste products of metabolism, in man are bean-shaped organs about 4-1/2 inches long lying behind the peritoneum in a mass of fatty tissue, and consist chiefly of nephrons by which urine is secreted, collected, and discharged into a main cavity whence it is conveyed by the ureter to the bladder.

concentrate

DEFINITION:

1. To bring to a common center; to gather together at one point.

2. To increase the strength by diminishing the bulk of, as of a liquid; to condense.

3. A drug or other preparation that has been strengthened by the evaporation of its non-active parts.

urine

DEFINITION:

The fluid excreted by the kidneys, passed through the ureters, stored in the bladder, and discharged through the urethra. Urine, in health, has an amber color, a slight acid reaction, a peculiar odor, and a bitter, saline taste.

AQP2

DEFINITION:

Aquaporin-2.

kidney

DEFINITION:

One of a pair of vertebrate organs situated in the body cavity near the spinal column that excrete waste products of metabolism, in man are bean-shaped organs about 4-1/2 inches long lying behind the peritoneum in a mass of fatty tissue, and consist chiefly of nephrons by which urine is secreted, collected, and discharged into a main cavity whence it is conveyed by the ureter to the bladder.

water reabsorption

DEFINITION:

collecting duct

DEFINITION:

regulated

DEFINITION:

2. In biology, describing the adaptation of form or behavior of an organism to changed conditions.

VP

DEFINITION:

Abbreviation for vasopressin.

AQP2

DEFINITION:

Aquaporin-2.

regulation

DEFINITION:

1. The act of adjusting or state or being adjusted to a certain standard. 2. In biology, the adaptation of form or behavior of an organism to changed conditions. 3. The power to form a whole embryo from stages before the gastrula.

AQP2

DEFINITION:

Aquaporin-2.

VP

DEFINITION:

Abbreviation for vasopressin.

apex

DEFINITION:

1. A general term used in anatomical nomenclature to designate the superior aspect of a body, organ, or part, or the pointed extremity of a conical structure such as the heart or lung; called also tip.

2. The point of greatest activity, or the point of greatest response to any type of stimulation, such as electrical stimulation of a muscle.

collecting duct

DEFINITION:

See under duct.

cell membranes

DEFINITION:

Plasma membranes

regulation

DEFINITION:

1. The act of adjusting or state or being adjusted to a certain standard. 2. In biology, the adaptation of form or behavior of an organism to changed conditions. 3. The power to form a whole embryo from stages before the gastrula.

water reabsorption

DEFINITION:

1. The act or process of absorbing water again.

2. Resorption.

regulation

DEFINITION:

1. The act of adjusting or state or being adjusted to a certain standard. 2. In biology, the adaptation of form or behavior of an organism to changed conditions. 3. The power to form a whole embryo from stages before the gastrula.

AQP2

DEFINITION:

Aquaporin-2.

concentration

DEFINITION:

1. Increase in strength by evaporation.

2. The ratio of the mass or volume of a solute to the mass or volume of the solution or solvent.

VP

DEFINITION:

Abbreviation for vasopressin.

regulation

DEFINITION:

1. The act of adjusting or state or being adjusted to a certain standard. 2. In biology, the adaptation of form or behavior of an organism to changed conditions. 3. The power to form a whole embryo from stages before the gastrula.

AQP2

DEFINITION:

Aquaporin-2.

expressed

DEFINITION:

1. Showing a detectable effect of a gene.

2. Made known; shown.

3. Squeezed out; extracted by pressing.

water balance disorders

DEFINITION:

Disorders caused by the disproportional relationship between the body's ingestion and excretion of water and electrolytes.

acquired nephrogenic diabetes insipidus

DEFINITION:

Nephrogenic diabetes insipidus produced by influences originating outside the organism, rather than caused genetically (i.e., congenital).

NDI

DEFINITION:

Nephrogenic diabetes insipidus.

regulation

DEFINITION:

1. The act of adjusting or state or being adjusted to a certain standard. 2. In biology, the adaptation of form or behavior of an organism to changed conditions. 3. The power to form a whole embryo from stages before the gastrula.

AQP2

DEFINITION:

Aquaporin-2.

congestive heart failure

DEFINITION:

A clinical syndrome due to heart disease, characterized by breathlessness and abnormal sodium and water retention, often resulting in edema. The congestion may occur in the lungs or peripheral circulation or both, depending on whether the heart failure is right-sided or general.

free water

DEFINITION:

That portion of the water in body tissues which is not bound by macromolecules or organelles.

body water

DEFINITION:

The water content of the human body. See also "total body water."

bound

DEFINITION:

1. Having formed a weak, reversible chemical bond, e.g., antigen to antibody or hormone to receptor.

2. Constrained by or as if by bonds; confined, obliged.

3. Enclosed in a binding or cover.

4. Resolved, determined; also, sure.

5. Intending to go.

6. Limit, boundary.

7. Leap, jump.

8. Rebound, bounce.

9. Spring, bounce.

organelles

DEFINITION:

A specialized cellular part (as a mitochondrion, lysosome, or ribosome) that is analogous to an organ.

binding

DEFINITION:

heart failure

DEFINITION:

Inability of the heart to pump blood at an adequate rate to fill tissue metabolic requirements or the ability to do so only at an elevated filling pressure. It can be defined clinically as a syndrome of ventricular dysfunction accompanied by reduced exercise capacity and other characteristic hemodynamic, renal, neural, and hormonal responses.

sodium

DEFINITION:

A silver white soft waxy ductile element of the alkali metal group that occurs abundantly in nature in combined form and is very active chemically.

concentrations

DEFINITION:

1. Increases in strength by evaporation.

2. The ratios of the mass or volume of a solute to the mass or volume of the solution or solvent.

kidney

DEFINITION:

One of a pair of vertebrate organs situated in the body cavity near the spinal column that excrete waste products of metabolism, in man are bean-shaped organs about 4-1/2 inches long lying behind the peritoneum in a mass of fatty tissue, and consist chiefly of nephrons by which urine is secreted, collected, and discharged into a main cavity whence it is conveyed by the ureter to the bladder.

AQP2

DEFINITION:

Aquaporin-2.

apex

DEFINITION:

1. A general term used in anatomical nomenclature to designate the superior aspect of a body, organ, or part, or the pointed extremity of a conical structure such as the heart or lung; called also tip.

2. The point of greatest activity, or the point of greatest response to any type of stimulation, such as electrical stimulation of a muscle.

cell membrane

DEFINITION:

Plasma membrane.

control rats

DEFINITION:

A group of rats differing from that under study (the treated or case group) by lacking the disease or by having a different or absent treatment or regimen; the controls and case or treated subjects usually otherwise have certain similarities to allow or enhance comparison between them.

apex

DEFINITION:

1. A general term used in anatomical nomenclature to designate the superior aspect of a body, organ, or part, or the pointed extremity of a conical structure such as the heart or lung; called also tip.

2. The point of greatest activity, or the point of greatest response to any type of stimulation, such as electrical stimulation of a muscle.

cell membrane

DEFINITION:

Plasma membrane.

regulation

DEFINITION:

1. The act of adjusting or state or being adjusted to a certain standard. 2. In biology, the adaptation of form or behavior of an organism to changed conditions. 3. The power to form a whole embryo from stages before the gastrula.

AQP2

DEFINITION:

Aquaporin-2.

cell membranes

DEFINITION:

Plasma membranes

water channels

DEFINITION:

Channels in a cell membrane that permit passage of water molecules; chemical substances such as vasopressin cause the opening of new channels and increase permeability.

collecting duct

DEFINITION:

See under duct.

cell membranes

DEFINITION:

Plasma membranes

water permeable

DEFINITION:

Permitting passage of water.

concentration

DEFINITION:

1. Increase in strength by evaporation.

2. The ratio of the mass or volume of a solute to the mass or volume of the solution or solvent.

sodium

DEFINITION:

A silver white soft waxy ductile element of the alkali metal group that occurs abundantly in nature in combined form and is very active chemically.

regulation

DEFINITION:

1. The act of adjusting or state or being adjusted to a certain standard. 2. In biology, the adaptation of form or behavior of an organism to changed conditions. 3. The power to form a whole embryo from stages before the gastrula.